英文翻译及文献_电子电子_功率半导体.doc

New Generation of High Power Semiconductor Closing Switches for Pulsed Power ApplicationsI. Introduction Solid state semiconductor switches are very inviting to use at pulsed power systems because these switches have high reliability, long lifetime, low costs during using, and environmental safety due to mercury and lead are absent. Semiconductor switches are able to work in any position, so, it is possible to design systems as for stationary laboratory using, and for mobile using. Therefore these switches are frequently regarded as replacement of gas-discharge devices ignitrons, thyratrons, spark gaps and vacuum switches that generally use now in high-power electrophysical systems including power lasers.Traditional thyristors (SCR) are semiconductor switches mostly using for pulse devices. SCR has small value of forward voltage drop at switch-on state, it has high overload capacity for current, and at last it has relatively low cost value due to the simple bipolar technology. Disadvantage of SCR is observed at switching of current pulses with very high peak value and short duration. Reason of this disadvantage is sufficiently slow process of switch-on state expansion from triggering electrode to external border of p-n junction after triggering pulse applying. This SCR feature is defined SCR using into millisecond range of current switching. Improvement of SCR pulse characteristics can be reached by using of the distributed gate design. This is allowed to decrease the time of total switch-on and greatly improve SCR switching capacity. Thus, ABB company is expanded the semiconductor switch using up to microsecond range by design of special pulse asymmetric thyristors (ASCR). These devices have distributing gate structure like a GTO. This thyristor design and forced triggering mode are obtained the high switching capacity of thyristor (=150kA, =50s, di/dt = 18kA/s, single pulse). However, in this design gate structure is covered large active area of thyristor (more than 50%) that decrease the efficiency of Si using and increase cost of device.Si-thyristors and IGBT have demonstrated high switching characteristics at repetitive mode. However, such devices do not intend for switching of high pulse currents (tens of kiloamperes and more) because of well-known physical limits are existed such as low doping of emitters, short lifetime of minority carriers, small sizes of chips etc.Our investigation have obtained that switches based on reverse switched dinistors are more perspective solid-state switches to switch super high powers at microsecond and submillisecond ranges. Reverse switched dinistors (RSD) is two-electrode analogue of reverse conducting thyristor with monolithical integrated freewheeling diode in Si. This diode is connected in parallel and in the back direction to the thyristor part of RSD. Triggering of RSD is provided by short pulse of trigger current at brief applying of reversal voltage to RSD. Design of RSD is made thus that triggering current passes through diode areas of RSD quasiaxially and uniformly along the Si structure area. This current produces the oncoming injection of charge carriers from both emitter junctions to base regions and initiates the regenerative process of switch-on for RSD thyristor areas. Such method of triggering for this special design of Si plate is provided total and uniform switching of RSD along all active area in the very short time like as diode switch-on. The freewheeling diode integrated into the RSD structure could be used as damping diode at fault mode in the discharge circuit. This fault mode such as breakdown of cable lines can lead to oscillating current through switch.It has been experimentally obtained in that semiconductor switches based on RSD can work successfully in the pulsed power systems to drive flash lamps pumping high-power neodymium lasers. It was shown in that RSD-switches based on RSD wafer diameter of 63 mm (switch type KRD-25-100) and RSD-switches based on RSD wafer diameter of 76 mm (switch type KRD-25-180) can switch the current pulses with submillisecond duration and peak value of 120 kA and 180 kA respectively. Three switches (switch type KRD 25-180) connected in parallel were successfully tested under the following mode: operating voltage = 25 kV, operating current Ip = 470 kA, and transferred charge Q = 145 Coulombs.During 2000 2001, the capacitor bank for neodymium laser of facility LUCH was built at RFNC-VNIIEF. This bank including 18 switches type KRD-25-100 operates successfully during 5 years without any failures of switches.This report is submitted results of development of new generation of solid state switches having low losses of power and high-current switching capacity.II. Development of RSDs next generation The technology of fabrication of new RSD structure has been developed to increase the switching capacity. This new structure is SPT (Soft Punch Through)-structure - with “soft” closing of space-charge region into buffer n-layer.Decreasing of n-base thickness and also improving of RSD switch-on uniformity by good spreading of charge carriers on the n-layer at voltage inversion are provided decreasing of all components of losses energy such as losses at triggering, losses at transient process of switch-on, and losses at state-on. Our preliminary estimation was shown that such structure must provide the increasing of operating peak current through RSD approximately in 1.5 times.Investigations were carried out for RSD with blocking voltage of 2.4 kV and Si waferdiameters of 63, 76, and 100 mm by special test station. The main goal of these investigations is definition of maximum permissible level of peak current passing through single RSD with given area. Current passing through RSD and voltage drop on RSD structure during current passing are measured at testing. In Fig.1 waveforms of peak currents and voltage drops is shown for RSD with size of 76 mm and blocking voltage of 2.4 kV.Fig.1. Waveforms of pulse current (a) and voltage drop (b) for RSD with wafer size of 76 mm and blocking voltage of 2.4 kVIn according with study program current was slowly increased until maximum permissible level Ipm. When this level was reached the sharp rise of voltage and than the same sharp decay of voltage for curve U(t) was observed. Reason of voltage rise is strong decreasing of carrier mobility at high temperature, and reason of voltage decay is quick modulation of channel conductivity by thermal generated plasma that is appeared in accordance with sharp exponential dependence for own concentration of initial silicon into base areas of RSD at temperature of 400 C.Tests were shown that this sharp rise of voltage at maximum permissible current does not lead to immediate fault of RSD. RSD keeps its blocking characteristic. However, after passing of such current we can observe the appearance of erosion from cathode for aluminum metallization of RSD contacts, and this fact is evidence of borderline state of device. The subsequent increasing of current (more than ) leads to fusing of Si structure. Therefore, level Ipm is the reference position to define the value of operation peak current for RSD-switch under long and repeated many times operating mode. We have determined that operating peak current must be less than 80% from level . This ratio was confirmed by calculations and results of tests under mode (several thousands of shots). Data of test results for new generation of RSD with the various diameter of Si wafer are shown in Table 1. In this Table for comparing results of the same tests for the first generation of RSD with size of 63 and 76 mm are shown. III. Switches based on RSD of new generation New reverse switched dinistors is manufactured in two variants. RSD of the first variant is in the low-profile metal-ceramic housing. The second variant is RSD fabricated without housing and with additional protection of periphery area from external action.Dinistors placed into housing can be used for work under as mono - pulse mode and repeated - pulse mode. If repeated-pulsed mode using the forced cooling of semiconductor devices and using of heatsinks to both side of pellet must be made. Dinistors without housing connects in series, and such assembly could be placed into a single compact housing. However, such assembly can work under mono-pulse mode only.Operating voltage for switch typically exceeds blocking voltage of single RSD (2400V), thus switch is included several RSDs connected in series. Fig.2. Reverse switched dinistors for peak current from 200 kA to 500 kA and blocking voltage of 2400 V, encapsullated in hermetic metal ceramic housing and without housing (RSD sizes of 64, 76, and 100 mm).Number of RSDs included in assembly depends on operating voltage of switch. Therefore, technical problem of switch development is mainly optimization of design for assembly of several dinistors connected in series. A lot of special investigations have carried out such as choice of optimum materials to provide best contacts between RSDs, calculation of dynamic forces to clamp assembly, etc. These investigations are provided small and stable transition electrical and thermal resistances between RSDs that guarantees long and reliable performance of switch. Especial computer technique has developed to select RSDs for connection in series. At this RSD selection value of leakage current and stability of blocking volt-amps diagram are measured especially. This selection technique is allowed exclude the voltage dividers using for equalization of static voltage for each RSD at assembly. Thus, after such selection switch design can simplify, sizes of switch are increased approximately in 1.5 times, and cost of switch is increased too.This solid state switch has operating voltage of up to 25 kVdc, operating peak current of up to 300 kA at current pulse duration of up to 500 s. RFNC-VNIIEF plans to use such switch at capacitor bank of laser facility “Iskra-6”. This switch is included 15 RSDs with size of 76 mm and blocking voltage of 2.4 kV connected in series and encapsullated into dielectric housing. Very high level of switched power density per volume unit has reached by this switch design. This value is of 2.5 W/, and this value is exceeded in the several times the same switches based on pulse thyristors.Triggering of all RSDs in switch is provided by the single trigger generator which connected to switch in parallel. Triggering current passes simultaneously through all RSDs connected in series. Such triggering type is allowed to increase efficiency and reliability of triggering circuit for this switch, and this is one more advantage of RSD switch compared to switch based on thyristors.For new generation of RSD trigger current has peak value between 1-1.5 kA at pulse duration between 1.5 2 s. These values are less in 2-3 times compared to values of trigger current for RSD of the first generation.IV. Conclusion Next generation of reverse-switched dinistors and RSD switches has been developed Tests of these switches are shown that all time high level of switched power density per volume unit has reached. The switches are able to work under as mono-pulse and pulse-repeated modes and suitable for many applications of pulsed power.应用于脉冲电源设备的新一代高功率半导体关闭开关一 导言 Solid state semiconductor switches are very固态半导体开关普遍使用在脉冲功率系统，因为these switches have high reliability, long lifetime,这些开关具有可靠性高，寿命长， low costs during using, and environmental safety使用成本低，并且due to mercury and lead are absent.由于汞和铅的量少能够保证环境的安全。Semiconductor半导体switches are able to work in any position, so, it is开关可以在任何位置工作，所以，它可以possible to design systems as for stationary在固定的laboratory using, and for mobile using.实验室使用，并可以为移动设备设计系统。Therefore因此these switches are frequently regarded as这些开关被频繁的看作是可以替代replacement of gas-discharge devices ignitrons,气体放电装置、放电管、thyratrons, spark gaps and vacuum switches that闸流管，火花隙缝隙和现在普遍使用的高能量电板systems including power lasers.系统包括功率激光器的真空开关generally use now in high-power electrophysical。Traditional传统的thyristors晶闸管(SCR)（()da are()是semiconductor switches mostly using for pulse大多应用在脉冲devices.设备的半导体开关。它在早前的SCR has small value of forward voltage正向电压drop at switch-on state, it has high overload下拉开关的状态有小的价值，它对电流具有超负荷的能力，最后它由于简单的两极技术它拥有相对较低的cost value due to the simple bipolar technology.成本价值。Disadvantage of SCR is observed at switching of它的缺点是高峰值的current pulses with very high peak value and short电流脉冲和duration.较短的持续时间。导致这种缺点的原因是在触发脉冲设置后从触发电极到到外部连接进程十分缓慢triggering electrode to external border of pn。This SCR。它的这种特征使得它应用在现时配电的毫秒范围内。改进晶闸管脉冲的特点可以通过改进分布式门设计达到效果。这就允许减少这就允许这the time of total switch-on and greatly improve总的接通时间和极大提高配电的能力。Thus, ABB company isThus, ABB company is因此，ABB公司扩大半导体开关的使用一直到对特别脉冲的不均匀asymmetric thyristors (ASCR) 1.晶闸管的微秒范围的设计。这些装置分布闸门的结构类似于GTOGTO。This这个thyristor design and forced triggering mode are晶闸管的设计和强迫的触发模式obtained the high switching capacity of thyristor获得晶闸管的高配电能力(I。However, in this design gate structure is covered然而，这个门的结构覆盖large active area of thyristor (more than 50%) that了晶闸管的大活动面积decrease the efficiency of Si using and increase cost，从而降低了硅利用的效率并增加了装置的成本。Si-thyristors and IGBT have demonstrated硅晶闸管和IGBT已经证明在重复模式下的high switching characteristics at repetitive mode高配电特性2,3.。However, such devices do not intend for然而，这样的设备因为众所周知的屋里限制不打算供给switching of high pulse currents (tens of kiloamperes高脉冲电流的配电普遍存在and more) because of well-known physical limits are，如存在使用兴奋剂的排放低， of minority carriers, small sizes of chips etc.少数载流子的载波寿命短，小尺寸的芯片等。Our investigation have obtained that我们的调查已取得的switches based on reverse switched dinistors 4基于逆向的接通在毫秒和微妙范围内接通显现为从使用电晶体管转换为接通高能量开关。Reverse switched dinistors逆向在硅里的综合的单片电路惯性滑行的二极管逆向的晶闸管conducting thyristor with monolithical integrated的的(RSD) is two-electrode analogue of reverse是两极类似物。这个二极管平行的连接，在后方与RSD的晶闸管部分连接。Triggering of RSD is provided by short触发RSD为提供短期pulse of trigger current at brief applying of reversal触发脉冲电流简短逆转的应用voltage to RSD.电压区。RSD的设计触发电流通过二极管领域的相对标准偏差quasiaxially and uniformly along the Si structure和均匀沿着硅的area.结构范围。目前生产的这即将来临的电荷携带者的生产过程从发射连接到基本区域和启动再生过程开关上的RSD为晶闸管地区。Such method of这种提供RSD开关的总和或统一的设置对于硅的特别设计的触发方法在非常少的时间应用在所有的活动面积类似二极管的接通。The freewheeling diode integrated into该惯性滑行的二极管集成到RSD结构可以作为阻尼二极管在fault mode in the discharge circuit.故障模式的放电电路。这种故障模式such as breakdown of cable lines can lead to如故障的电缆线可能会导致oscillating current through switch.振荡电流开关通过。It has been experimentally obtained in 它已获得的RSD为基础的实验半导体开关can work successfully in the pulsed power systems可以成功地在脉冲功率系统to drive flash lamps pumping high-power内内推动闪存灯泵浦高功率的neodymium lasers.得得钕激光。结果表明在该区域市交换机基于RSD为晶圆直径六三毫米和RSD开关的on RSD wafer diameter of 76 mm (switch type关于区晶圆直径为76毫米可以切换当前的脉冲submillisecond duration and peak value of 120 kA持续时间和峰值。三个开关并联successfully tested under the following mode:成功试射以下模式：经营电压= 25 kV, operating current I = 25 kV，经营电流= = 470 kA, and transferred charge Q = 145 Coulombs 470 kA，并转移电荷= 145 库。During 2000 2001, the capacitor bank for 在2000 - 2001年，电容器neodymium laser of facility LUCH was built at钕激光射线的设施建在RFNC-VNIIEF 7. RFNC - VNIIEF。这种电容器组，包括类型KRD - 25 100的18个开关，type KRD-25-100 operates successfully during 5成功地没有任何失败的经营了5 years without any failures of switches.年开关。This report is submitted results of 本报告提交结果development of new generation of solid state发展新一代的固态switches having low losses of power and high-开关，具有低功耗和损失高current switching capacity.的交换容量。二 Development of RSDs next generationRSDRSD下一代的发展新的RSD结构的制造技术The technology of fabrication of new RSD已经发展意境已经发展用于增加开关的容量。这种新的结构标准贯入试验结构与“软”闭幕space-charge region into buffer n-layer.空间电荷区域变成缓冲层。Decreasing of n-base thickness and also通过电压转变在缓冲层上的交换载体的良好传递，氮基厚度的减少和提高RSD开关的均匀被提供降低所有损失能量的组成成分，像扳机的缺损、开关过程短暂的缺损以及基层的缺损。我们的初步估计was shown that such structure must provide the结果表明，这种结构必须通过RSD使运转电流的峰值不断增加increasing of operating peak current through RSD，approximately in 1.5 times.大约在1.5倍以上。Investigations were carried out for RSD调查进行了阻断电压为2.4 kV及硅晶片diameters of 63, 76, and 100 mm by special test直径为63、76 和100毫米的特殊测试站。这些测试的主要目标是测定在已给范围内通过单个RSD的definition of maximum permissible level of peak最大允许水平的高峰current passing through single RSD with given area.电流。在电流通过的瞬间，Current passing through RSD and voltage drop on通过RSD的电流和在RSD结构上的电压都在测试中被测量。在图一中，电流峰值的波形和电压的通过用尺寸为76毫米，阻断电压为2.4千伏的RSD显示。直到最大许可等级为I极，电流研究项目的一致慢慢的增加pm。当这个极达到，对电压的尖锐程度和同一衰减电压for curve U(t) was observed.曲线U进行了观察。电压上升的原因是在高温度情况下的自动载体的强大增加is strong decreasing of carrier mobility at high，电压衰减的原因是通过generated plasma that is appeared in accordance产生的等离子体，据with sharp exponential dependence for own同时还存在尖锐的指数，热传导的快速modulation of channel conductivity by thermal调节调节依赖自己在温度为400-600度的RSD的基础领域，concentration of initial silicon into base areas of初始浓度的硅集成度 RSD at temperature of 400 600。 Tests were shown that this sharp rise of试验表明，在最大允许电流上通过的电压的尖锐程度不会导致RSD的直接错误。RSD保持着其blocking characteristic.阻断特性。However, after passing of然而，在通过这种I极such current I电流之后，我们可以观察到RSD连接的铝金属的负极被侵蚀的现象we can observe the appearance of，这一事实是设备交界层的证明。随后电流的增加导致硅结构的熔合。Therefore, level I因此，I极是RSD开关在长期反复多次经营模式下，确定操作峰值电流的相对标准偏差的参考位置。图一.尺寸为76毫米和阻断电压为2.4千伏的RSD的脉冲电流波形（ a ）和电压降值（ b ）We have determined that operating peak我们已认定， current I电流操作峰值I极必须must be less than 80% from level I小于80%。This ratio was confirmed by calculations and results这一比例也证实了我在I极模式下的计算和测试结果of tests under Ipw。Data of test results for new generation of。多种直径的硅金属促成的新一代的RSD测试结果数据显示在图一shown in Table 1.。在同一测试中的比较结果在此表中，第一代的尺寸为63和76毫米的RSD被显示。三 基于新一代的RSD开关 New reverse switched dinistors is 新的转变晶体管开关被制造成两种模式。第一种RSD是variant is in the low-profile metal-ceramic housing.低姿态的金属陶瓷机架。The second variant is RSD fabricated without第二种是RSD不通过机架制造，而是通过来自外围区域的额外的保护。晶体管Dinistors placed into housing can be used置入可用于在单-脉冲模式和反复-pulse mode.脉冲模式的机架下工作。如果重复使用脉冲模式下forced cooling of semiconductor devices and using强制冷却的半导体器件，两边of